Rules of Logic

The famous expert Drongo received an unexpected order. The "Wine King" of Europe and billionaire Edward Harrison invited him to his French villa and asked him to find extremely important documents stolen from his London office. Edward suspects that one... of his relatives, who are also gathered at the villa, did it. That very evening, the billionaire was shot dead at close range with a pistol. The crime took place in a small room, isolated from the outside world, and Drongo was literally next to the door. But when he burst in after hearing a noise, there was only a corpse inside... Where did the criminal go and who was it? There are no clues, and Drongo decides to resort to pure logic…